Is the best flashlight I have ever had. Took advantage of the Fenix LD20 and had been for a defective switch. So I ended up in the SRT3 of NiteCore. Use it whenever you "use". As a battery, I use a CR1234 battery to get the full 550 lumens. The price is steep, but the build quality and light output is true. Who can not bear the high price tag gets a great torch.